Apparatus for cementing wells



Feb. l, 1949- s. A. WINKE'Llvl/abm: 2,460,56

APPARATUS FOR GEMENTING WELLS Filed oct. 13, 1944 2 sheets-sheet 1 maw.'

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Feb. l. 1949. s, A, WINKELMANN 2,460,561

APPARATUS FQR CEMENTING WELLS Filed ost. 1 3,l 19544 2 sheets-snee*u 2 IN V EN TOR.

SAMUELAWmKELMANN BY wwa A rra/Pmi K Patented Feb. 1, 1,949

SamnelA. Winkelmann, Honston,

of one-half to W. L. Goldston, Houston,

ir-ENT oFFlcl;

Tex., assigner Tex.

Application October 13, 19;@1, Serial No. 558,555

1 The invention relates to a means for cementing pipe in welle 2 claims. write-i) The present invention contemplates the accurate rpositioning of the cement"withoutchanneling or contamination ofY thev cement 'by drilling mildinthewell. i'

Anth'er'objeCt of the invention is to provide a vskirt into which the cement being pumped out of the casing' will be directed so that the skirt will form a barrier between the cement andthe mnd in the well and no cement'may pass the skirt and no mud will contaminate the cement as the skirt moves along ahead of the Cement,

Another object of the invention is to provide a barrier about the pipe in a well bore which will slide along the pipe under the pressure of the cement-being introduced lso as to displace the other liquid in the well, to wipe the pipe, and -to scratch the yformation so as to permit lthe oement to form aibond therewith.

Another object oi the invention is to provide a cementing skirt comprising an annular ring supporting ra afed skirt like portion which will scratch the surface of the well bore while the ring oarries'e) portion to engage and wipe the PPEPS it 511.535 .avpfng- Still another object of the invention is to pro" vide a, cementingassemblm.including a oat col lar and guide shoe, a cementing skirt, and a releasable latch for theskirt. Y

Still another object of the invention is toprovide a cementing,.skirtgwdiichTwillrbe released by the application of pressure to the cement which will move alongahead of the cement to prevent .contamination .of .the jcementlwith the drilling. mnd.

v'Other and. furthenobjects. of. the invention will be `readily apparent when the. following description is.considered.inconnectionwith the accompanying drawings, wherein:

Fig. 1 is a vertical sectional View of the cementing assembly as it is being lowered into the well bore.

Fig. 2 shows the cernenting assembly with 'the cementing skirt being released,

Fig. 3 shows the cementing assembly with pressure being applied to the cement, so as to effect movement of the skirt and displacement oi the drilling mud by the cement.

Fig. 4 is a section taken on the line of Fig. 3.

In Fig. l a string of pipe or casing 2 is being lowered into the well bore and has a cement collar 3 threaded at Il thereto.

This cement collar is part of a cementing as- S as the barrier slides along snchv surface.

vsembly which is made up of a nipple 5 threaded lat fi'to a back pressure valve body l whichin turn has the pipe 8 vthreaded into it so as to supportthe' guide shoe It).

The back pressure valve body 'l has the passage ll therethrough provided with a shoulder 'l2 to form a 'seat for the ball valve i3. In this manner, when there is a predominant pressure from below, the ball will remain in its seat as seen in` Fig. l. If, however, there is a predominant pressure from above, the ball i3 will move 'down into'the cage Ed which serves to catch 'and retain the Vball as seen in Fig. 2.

`lA means in the form of a scavenger plug l@ made up cfa cylindrical body il and the wiper 'i8 has 'a vertical passage Eil therethrough. A pair 'of rangible disks 2t and 22 are carried in spaced relation closing the vertical passage I9. These disks confine a ball 23 between them and it lwill be noted that this ball is somewhat smaller than .the check valve 23. Such ball acts as a cement retainer skirt release member as will be later described. The shoe iii has a semi-spherical ,base portion having a passage 25 therathrough. Arranged around the pipe portion il is a barrier orskirt ii in thev form of a ring or collar 3l which is offset at f2 to provide a seat for the wiper rings 33 oi suitable `dexible material, so as to wipe the peripheral surface :it of the pipe In this manner-the surface 3Q will be cleaned so as to facilitate the bonding of the cement thereto.

,.his support ring 3l carries a cementing skirt or barrieri which may also be designated as a cement"retainer yskirt which is made up of a exiblehoilow frusto-oonica1member Se which may be made of rubber, reinforced canvas, or any 'suitable fabric material which can be collapsed or'foldecl in'to `theposition in Fig. l or extended as seen in Fig. 2. This material may be reinforced by a plurality of spring iingers 3l anchored by a retainer ring 38 and which normally have a configuration shown in Fig. 2, but which may be collapsed to the position oi Fig. l. These fingers each carry a sharp prong 39 which is arranged to scrape into the surface it of the well bore ii, in which the assembly has been positioned.

These prongs are shown at 39 in Fig. 2 as penetrating the surface i0 so as to scratch the surface and ronghen it so as to allow the cement to move into such areas to increase the bond of the cement with the wall of the well.

When the assembly is being lowered into the well, this skirt 35 will be collapsed as seen in Fig. 1 with the bent over ends I4 of the fingers 3l engaging underneath the rib 45 on the periphery of the pipe 3. This anchors the skirt from sliding movement along the pipe when the assembly is being lowered into the well.

In order to confine the skirt 35 as seen in Fig. 1, a false bottom, latch cap, or shield 41 is iiitted over the shoe I and temporarily retained by a shear pin 48. This false bottom has its upper edge 49 over-lapping the lower ends of the lingers 31 so as to conne the skirt` The false bottom 4'I has an opening 50 in. the bottom thereof which is of a size to prevent the ball 23 from passing therethrough. Y

In actual operation, the pipe 2 and the cementing assembly will be connected together with the parts in the position in Fig. 1, except that the scavenger plug I6 may not be in position. As the pipe is oated into the well, the desired amount of liquid may be added in the form of water or drilling mud so that the desired flotation effect is obtained and the pipe 2 is prevented from collapse due to the pressure in the well bore.

Either before or when the pipe is landed at the proper point, the scavenger plug I6 can be introduced at the top and cement applied to the upper surface. As the cement is pumped in, the scavenger plug will move downwardly in the pipe 2 until it arrives at the -position shown in Fig. 1. Any liquid in the pipe will unseat the valve I3 and pass out through the bottom openings 2'5 and 50. When the scavenger plug engages the float valve body l, it will be prevented from further movement. The pressure on the cement will rupture the disks 2| and 22, driving the .ball 23 downwardly until it strikes the float valve I3. The continuous pressure then moves the iloat valve I3 downwardly into the cage I4 and allows the ball 23 to pass outwardly through the cage around the valve i 3. The cement continues down through the openings I9 and I I as indicated by the arrow 52, in Fig. 2, the ball 23 will be forced downwardly through the opening 25 and is received in the opening 50 in the false bottom 41. The valve 23 thus closes the assembly but the continued application of Vpressure will shear the pin i8 and force the false bottom downwardly from over the ends of the iingers 31 so that the skirt 35 is released and will spring outwardly clue to the provision of the spring lingers 31, The continued pressure causes the false bottom to move away from the shoe I0 and the cement will now discharge through the opening 25 into the area 55 which will fill with cement. The pressure is continued so that the cement will be forced into the skirt 35. As the cement continues to discharge, the movement of the cement will force the skirt or barrier upwardly along the pipe on top of the cement so that it forms a partition between the drilling mud '56 and the cement material 5'I as best seen in Fig. 3,

The ring and skirt assembly tend to center the pipe in thewell, the Wiper rings 33 tend to clean the surface 34 of the pipe so that the cement will bond therewith, and the scratcher prongs 39 tend to scrape the surface 40 of the well bore, so that the cement will also bond with the earthvformation.

One of the principal advantages of this skirt or barrier resides in the fact that none of the cement can pass the barrier, that the barrier is moved by the pressure on the cement and in this manner there can be no channeling of the cement through the drilling mud and there can be no contamination of the cement with drilling mud. The Vgreater the pressure on the cement, the greater will be the tendency of the skirt to expand and ride along ahead of the cement.

What is claimed is: A

l. The combination of a pipe in a Well to be cemented and a cementing assembly including a iloat valve in the pipe, a latch release means above said valve but adapted to pass thereby upon the circulation of fluid under pressure past said valve, a slidable skirt about the pipe, means latching the skirt in collapsed position, said means being releasable by said latch release means in response to the movement of said latch release means thereagainst by fluid pressure.

2. A well cementing assembly attached to the lower end of a pipe comprising a guide shoe and float collar, a latch cap enclosing said guide shoe, a cementing skirt slidably arranged around said pipe and initially latched in collapsed position by said cap, an opening in said guide shoe and means movable through the shoe by the pressure applied to the cement to engage and detach said cap from the pipe and release said skirt so that such skirt opens to form a barrier between the cement discharged from said guide shoe and the fluid in the well and slides upwardly on top of the cement, and serves to confine the cement to center the pipe, to disperse Vthe cement and to avoid channeling.

SAMUEL A. WINKELMANN.

REFERENCES CITED The following references are of record in the le of this patent:

FOREIGN PATENTS Number Country Date 2,150,310 Baker Mar. 14, 1939 2,212,086 Thornhill Aug. 20, 1940 2,263,566 Boynton Nov. 25, 1941 2,335,387 Cantin Nov. 30, 1943 2,344,120 Baker Mar. 14, 1944 

